1. Field of the Invention
This invention relates to an irrigation system for a field area and more particularly to an irrigation system for watering the corners of a field which is irrigated by a center pivot irrigation machine or system. More particularly, the irrigation system of this invention employs a plurality of spaced-apart, in-line emitters imposed in distribution water lines which are buried beneath the surface of the field in the corners of the field.
2. Description of the Related Art
There are an estimated 62.4 million acres of land irrigated in the United States. Of this area, about 30 million acres are irrigated with sprinkler irrigation. There are also 4.3 million acres irrigated by low flow techniques. Of the 30 million acres irrigated by sprinklers, some estimates show about 20 million acres are irrigated by center pivot irrigation machines or systems. Most center pivot fields do not have a corner system. If all of the center pivot irrigated land were in square quarter sections, there would be approximately 4.4 to 5.4 million acres in the corners. Most of these acres lay barren, or are farmed in a dry land manner; therefore, there is a need to irrigate these corners.
The center pivot industry has elected to solve the corner irrigation problem with a highly complex, short-life, and expensive corner attachment. While corner systems have been effective in some locations, and on some crops, corner systems have not been widely adopted in the central part of the United States. Nebraska, with its 8 million acres of irrigated land; Texas, with its 6.5 million of irrigated land; and California, with its 9.6 million acres of irrigated land, do not employ an abundance of corner systems which may be dependent upon the unreliability of the systems and the lack of uniformity of water pattern. Further problems are the fact that the corner systems get stuck and create wheel tracks in the corners of the fields. A further possible disadvantage of the corner irrigation systems is that the installed cost of a corner system (to the grower) is approximately $29,000, or a per acre cost of about $1,100 for each irrigated acre under the hardware. The cost of corner systems compares approximately to the cost of low flow technology systems.
Certain drip tape manufacturers are promoting use of varied drip tape in the corners of the field. Buried drip tape in the corners of the field have been researched and rejected (in most cases) because of the problems that the tape industry has with buried tape. The tape may plug and the grower may not realize the same, thus leading to reduced yields. The buried drip tape may need replacing in a short time if it cannot be unplugged. Some persons are of the belief that buried drip tape will not work on sandy fields. It is believed by some that the inability of the drip tapes to function properly is the inability of the same to adequately supply water to the areas adjacent the discharge openings and to prevent plugging or clogging of those discharge openings.